1. Field of the Invention
The present invention relates to an intake air control device includes a valve shaft which extends across an air intake path of an air intake path forming body. The valve shaft is rotatably supported by the air intake path forming body, which is connected to a cylinder head of an engine body mounted to a vehicle body frame of a saddle type vehicle. A butterfly-shaped throttle valve is fixed to the valve shaft so as to control the opening of the air intake path. An actuator is connected to an end of the valve shaft, and includes an electric motor. The motor is moved according to a detected value of a throttle operating amount sensor for detecting the throttle operating amount by a vehicle operator.
2. Description of the Background Art
In a known intake air control device, an actuator, including an electric motor, is connected to an end of a valve shaft. The valve shaft is rotatably supported by an air intake path forming body for controlling the amount of intake air of an internal combustion engine to be mounted to a vehicle. Such an intake air control device is disclosed, for example, in JP-A-4-203431.
According to the intake air control device disclosed in JP-A-4-203431, a throttle operating amount sensor is provided. The throttle operating amount sensor detects the operating amount of an accelerator pedal, which corresponds to the throttle operating amount input by a vehicle operator. The throttle operating amount sensor is arranged in the vicinity of the accelerator pedal. However, when this technology is applied to a saddle type vehicle, mounting of the throttle operating amount sensor to a steering handle in the vicinity of the throttle grip instead of the accelerator pedal makes the structure in the vicinity of the throttle grip complex, which may cause increase in weight of the steering handle. Although assembly of the throttle operating amount sensor to an air intake path forming body can be considered as an alternative mounting location, if doing so, the length of a throttle cable which is moved in response to the operation of the throttle grip increases, and hence friction of the throttle cable also increases.
In view of such circumstances, it is an object of the present invention to provide an intake air control device in which the length of the throttle cable, which is moved in response to the operation of the throttle grip, can be reduced while simplifying the structure of the steering handle in the vicinity of the throttle grip.